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United States Patent | 5,675,702 |
Gerson ,   et al. | October 7, 1997 |
A Vector-Sum Excited Linear Predictive Coding (VSELP) speech coder provides improved quality and reduced complexity over a typical speech coder. VSELP uses a codebook which has a predefined structure such that the computations required for the codebook search process can be significantly reduced. This VSELP speech coder uses single or multi-segment vector quantizer of the reflection coefficients based on a Fixed-Point-Lattice-Technique (FLAT). Additionally, this speech coder uses a pre-quantizer to reduce the vector codebook search complexity and a high-resolution scalar quantizer to reduce the amount of memory needed to store the reflection coefficient vector codebooks. Resulting in a high quality speech coder with reduced computations and storage requirements.
Inventors: | Gerson; Ira A. (Schaumburg, IL); Jasiuk; Mark A. (Chicago, IL); Hartman; Matthew A. (Schaumburg, IL) |
Assignee: | Motorola, Inc. (Schaumburg, IL) |
Appl. No.: | 611608 |
Filed: | March 8, 1996 |
Current U.S. Class: | 704/223; 704/217 |
Intern'l Class: | G10L 009/08 |
Field of Search: | 395/2.25-2.32,2.38,2.39,2.92,2.95 |
4544919 | Oct., 1985 | Gerson | 381/41. |
4896361 | Jan., 1990 | Gerson | 381/40. |
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